Systems for automating the storage and distribution of containerized goods in warehousing and manufacturing facilities have bee developed to reduce the expense and errors associated with manual storage and distribution. Automated storage and distribution systems, such as that described in Grace, U.S. Pat. No. 4,621,745, can improve warehouse and manufacturing operation efficiency and inventory management. U.S. Pat. No. 4,621,745 discloses a container storage and dispensing assembly for use in an automated storage and distribution systems. The assembly includes two opposing stacks of vertically staggered shelf assemblies. The shelf assemblies receive containers at the top of the stacks and distribute the containers in zigzag fashion downward through the stacks to a dispensing location at the bottom of the stacks. Each shelf assembly is mounted relative to a support structure to pivot between an upwardly tilted receiving position, a substantially horizontal storage position, and a downwardly tilted discharge position. In operation, a shelf assembly in the upwardly tilted receiving position receives a container from a next higher shelf assembly that is in the downwardly tilted discharge position. The receiving shelf assembly pivots downwardly under the weight of the container and locks in the horizontal storage position if the next lower shelf assembly is not in the receiving position.
The next lower shelf assembly assumes the receiving position when it is empty. The upper shelf assembly is unlocked from the storage position by the upward movement of the next lower shelf assembly, and is thereby permitted to pivot downwardly to the discharge position to transfer the container to the next lower shelf assembly. In this manner, the container is moved downwardly through the stacks in sequential fashion until the lower-most shelf assemblies are filled with containers, and advance sequentially as containers are dispensed from the bottom of the stacks.
Grace, Sr., U.S. Pat. No. 5,111,963, discloses a storage and dispensing apparatus for articles, containers, and the like, in which vertically spaced shelf assemblies pivot between receiving and discharge positions. Biasing structure is provided to urge the shelf assemblies to the receiving position. A transfer stop is connected to the shelf assembly and has a lock position retaining the shelf in the receiving position when a shelf of a next lower shelf assembly is not prepared to receive a container, and a release position allowing the shelf to move to the discharge position under weight of a container disposed on the shelf when the shelf of the next lower shelf assembly is prepared to receive a container. A transfer control is operatively connected between the transfer stop and the next lower shelf assembly for transitioning the transfer stop to the release position when the next lower shelf is prepared to receive a container.
Stingel, Jr. et al., U.S. Pat. No. 5,236,104, discloses a multiple pressure container storage and retrieval apparatus with opposing stacks of vertically staggered shelf assemblies. Fluid operated structure is provided to raise the shelf between at least a downwardly tilted discharge position and an upwardly tilted receiving position. A higher pressure fluid source and lower pressure fluid source are provided. Container indicator switching structure connects the raising structure to the higher pressure fluid source if a container is not present on the shelf, and to the lower pressure source if a container is present on the shelf. Transfer control structure is operatively connected between the shelf and the next lower shelf, and is adapted to prevent the lowering of the shelf to the discharge position unless the next lower shelf is in the receiving position.
Stingel, Jr. et al., U.S. Pat. No. 5,285,928, discloses a fluid operated container storage and dispensing system with stacks of opposing, vertically staggered shelf assemblies. A fluid operated system maintains each shelf in an upwardly tilted receiving position until a container is received and prevents the lowering of the shelf to the discharge position until the next lower shelf is prepared to receive a container.
Stingel, Jr., U.S. Pat. No. 5,779,094, discloses an article reception system for storage and dispensing apparatus in which there are two opposing vertical stacks of shelf assemblies. A pivotally mounted cross-bar extends transversely across each shelf and is moveable between an article receiving position and an article arresting position. A respective damper is provided for arresting motion of each cross-bar when engaged by a conveyed article and moved from the article receiving position to the article arrested position. A bias urges each cross-bar from the article arrested position to the article receiving position. An optical sensor on each shelf can be provided for detecting an article's presence and supplying a control signal to the independently pivoting shelves in a coordinated manner.
Stingel, Jr. et al., U.S. Pat. No. 5,903,464, discloses a conveying system and method for mixing stacked articles in which a first conveying path originates at a first working station and terminates at a second working station. A second conveying path originates at the second working station. The first working station selectively moves homogeneous layers of articles from respective stacks to the first conveying path. The second working station receives the articles from the first conveying path and distributes the articles into selected ones of a plurality of vertical conveying and storage paths. The articles are supplied to the second conveying path from the vertical conveying and storage paths in a pre-determined sequence. The pre-determined sequence is established by defining control sequences for the moving, distributing, and supplying performed in the work stations. The articles conveyed on the second conveying path can be arranged into groups relating to the pre-determined sequence.
Vertically accumulating storage and dispensing apparatus having opposing assemblies of staggered, vertically spaced, shelf assemblies require biasing or some motive force to raise the shelf assembly to the article receiving position. Also, some biasing or motive force should be provided to dampen the motion of the shelf assembly from the receiving position to the discharge position under the weight of the container. The amount of bias or motive force will be dependent on the weight and position of the container on the shelf assembly. In systems where a variety of different containers, having different sizes and weights, must be handled by the storage and dispensing system, different biasing or motive forces are required depending upon the article or container that is being handled by a particular tower. This can require many different bias or motive force structures to handle the different containers or articles. This increases the complexity of the system, and also does not allow for rapid reconfiguration of the system when it is desired that a particular tower handle containers or articles having different size and weight characteristics than were handled by the tower previously.